Synchronizing clock system.



J. W. BRYCE.

SYNCHRONIZING CLOCK SYSTEM.

APPLICATION FILED OCT. 4. 1918.

1,310,785. Patented July 22, 19119.

W IgENTOR Y I17'CL. m. l u m W ATTORNEY- JAMES W. BRYCE, 0F BINGHAMTON, YORK.

SYNCHRONIZIN Gr CLOCK SYSTEM.

Specification of Letters Patent.

Patented July 22, 1919.

Application filed October 1, 1918. Serial No. 256,800.

To all whom it inay comer n:

Be it known that I, JAMES W. BRYCE, a citizen of the United States, residing at Binghamton, in the county of Broome and State of New York, have invented certain new and useful Improvements in Synchronizing Clock Systems, of which the following is a full, clear, and exact description.

In prior applications filed by me, notably in an application filed on May 21, 1918, Serial No. 235,813, I have shown and described a synchronizing clock system involving a master clock and any number of secondary clocks which are controlled by and synchronized with the master clock.

Generally speaking each secondary clock contains means for retarding or stopping it,

and other means for accelerating or advancing in, and the master clock connects with the line a source of current during predetermined intervals of given extent, which cur-' rent, if the clock be too fast, is directed by the establishment of conditions in the secondary clock through the means for retarding or stopping the clock until the master clock has caught up with it, or in a similar.

manner, if the clock be too slow, is directed through the means for accelerating it during the interval or period by which the secondary is behind the master clock.

In the latter case, if the accelerated rate of the secondary clock be sufficiently high, the said clock will catch up with the master clock in a relatively brief interval, but practical considerations render it difficult to im part to the clocks such a rate as will sufiice for this purpose. For example, we may assume as one practicable means for accelerating a clock, that the secondary clock has a differential gear member in its train thatmay be checked to stop the movements of the hands for any period, or may have both of its members free to rotate at normal rates whereby. the central driven member which controls the hands will move at double speed In such event, if the clock be five minutes slow with respect to the master clock its acceleration will continue for five minutes, during which period its hands will move at double speed, but this will not be suflicient to bring it into synchronism since in this period the clock will have gained only two and one half and not five minutes. If,therefore, the synchronizing current from the master clock comes for a definite period once an hour, the secondary clocks, even assuming they lose no further time, will theoretically .never be brought up to perfect synchronism, althoiigh their approximation thereto will be adequate for all practical purposes.

The invention, subject of this application, is an improvement in this system, by means of which true synchronism may be speedily and readily obtained in case the secondary clocks should fall behind the master clock, and the invention provides a practicable mechanism for accomplishing this purpose.

According to my present invention, therefore, I provide in the train of a secondary clock a differential gear, one member of which is provided with means for stopping its movement entirely, and the other member with a normally locked. esc'apement which, when released, permits said member to rotate at normal speed. These two members control a central member, which imparts movement to the hands of the clock.

lVhen both members are locked against movement, therefore, the hands are stopped, but when both members are allowed to rotate, a movement of double the rate of the normal is imparted to the central member and to the hands.

Associated with these devices is a means for prolonging the contact between the line and the releasing mechanism for one member of the differential to double the period by which a secondary clock may be behind the master clock so that when the clock is slow it may be accelerated for twice as long a period as it is slow before the differential member is again locked, whereby it will have a chance to catch up to the master clock during each period of current connection with the line thereby. Means are provided for returning the parts of the mechanism involved in this operation after each accelere tion of the secondary clock so that by this improvement perfect synchronism with the master clock may at all times be secured.

This improvement is illustrated in the accompanying drawings in which Figure 1 is a view largely diagrammatic of the mechanism contained in a secondary clock.

Fig. 2 is a sectional view of a clutch mechanism involved in the said means, and

' In the drawing, I have shown only, the

secondary clock. The master clock may be of any known construction, and for purposes of this case it may be assumed toconnect with the circuit reaching the terminals 1 and 2 of the secondary clock a source of current for a period of fifteen minutes each hour, say from fifteen minutes of the hour to the even hour. In my said application hereinbefore referred to, and in others, the means for doing this are fully shown, and as these may be of any known and desirable character, I have not illustrated them in detail in this case.

There may be any desired number of secondary clocks, and they are all of the same construction. Each clock. is provided with a driving train 3, of which 4 is the hour shaft, and. in the train of which this shaft is a. member is a difi'erential which is shown in detail in Fig. 3.. v

This diiferentialis composed of two side members '5 and 6, whichvare'rigidly connected with gears 7 and 8 engaging with gear wheels 9 on a central member 10 fixed to the spindle 11. The rotation of the members 5 and 6 determines the movement of the spindle l1, and their rate the rate of such move ment, as is well known to those skilled in this art.

In gear with the member 5 is an escapement 12, having a balance wheel 13 and associated with the latter is a finger carried by the armature 14: of an ele'ctro-magnet 15, and when this magnet is energized the finger contacts with the balance wheel and stops the member 5 from rotation.

In gear with the other member 6 is a similar escapement 16, similarly controlled by a finger 17 and an electro-magn'et 18, but when this magnet is not energized the finger 17 is in contact with the balance wheel and memher 6 is prevented from rotating.

On the hour spindle 4 is a cam Wheel 19 having a cut-away portionin its periphery.

The high part of the cam maintains a contact 20 out of engagement with another contact 21, but when by its rotation the cutaway part permitscontact 20 to drop, the latter closes the circuit 22, 22, including the electro-magnet 15. v

If the secondary clock be exactly on time the contacts 20, 21 are permitted to come 0- 'gether at the even hour, as shown by he hands of the secondary clock. But under the assumption made, at this instant the current sent to the line by the master clock is broken by the latter, hence circuit 22 is receivingno current and nothing happens.

Should-the secondary clock, however, be too fast, contacts 20, 21 close before the even hour, in which case magnet 15 will be enertherefore, be too slow, these contacts will be maintained in engagement until after fifteen minutes of the hour or during more or less of the period in which current is coming over the line from. the master clock. This current will accordingly flow through circuit 22, 25, which includes magnet 18, and hence the escapement 16 will be permitted to operate and the member 6 of the differential will turn at the normal rate. As at this time the member 5 is also turning the rotation of the central member will be twice normal speed, and the clock hands will be "advanced at double the normal rate.

Assume the secondary is five minutes slow; then for 2-; minutes the hands Wlll travel at twice their normal rate and at the end ofthe 22; minutes, or when the circuit 22, 25 is broken by the cam 23, the secondary will have made up 2% minutes, which is not enough.

In series, however,'with the contacts 24- are two contacts 27 which bear on rings 26 on a clutch magnet 28 on the hour shaft 4;. Hence, when current passes between contacts 24 this clutch magnet is energized and imparts rotation to a gear-wheel 29 that meshes with a pinion 30 carried by a plate 31 rotating about the hour shaft and upon whlch the contacts 24 are mounted. The pinionalso meshes with a fixed rack 32, hence as long as the clutch magnet remains energized the pinion is caused to travel up the rack at the normal rate-of the clock, and carries along with it the contacts 24.

From this it results that the contacts moving upward at one-half the rate as the cam 23, are maintained closed for twice the length of time they would otherwise be 1f not moved, hence the clock will have the full period of five minut s to catch. up in and at the expiration of th t per1od, when the cam permits the contacts-24 to separate, it is in exact synchronism with the master clock.

As soon as the circuit is thus broken, the clutch magnet 28 is denergized and the gear 29 and the plate 31 drop back into their normal position.

In the drawmg I have shown contacts 33 as adapted to be brought together by a cam disk 34 on the hour shaft for -predetermined intervals to cause the vibrating or interrupted direct current from the main llne to flow through "a win'd-ing magnet 35, but

It will be understood that current may be sent to line by the master clock at other intervals of greater or of less duration, and oftener than once an hour or less frequently,

but these are matters well within the skill of those familiar with'this art.

Having now described my invention What I claim is:

1. In a synchronizing clock system involving a master clock that connects to line a source of synchronizing current for predetermined periods of definite duration, the combination with each secondary clock of means for retarding or stopping the movement of the clock hands and means for accelerating such movement, circuit-controllers for connecting said means to the line for definite periods in fixed relation to the time indicated by the said clock, whereby the clock will be stopped if too fast or accelerated if too slow by the action of the line current the period of flow of which is overlapped by the periods of closure of the said circuit-controllers, and means for prolonging the period of engagement of'the contacts which direct such current to the accelerating means to compensate for a relatively slow rate of acceleration.

2. In a synchronizing clock system involving a master clock that connects with the line a source of synchronizing current for predetermined intervals of definite extent, the combination with each secondary clock of means for retarding or stopping the movement of the clock hands and means for accelerating such movement, circuit-controllers for connecting said means to the' line for definite periods in fixed relation to the time indicated by the said clock whereby the clock will be stopped if too fast or accelerated if too slow by the'action of the line current the period of flow of which is overlapped by the periods of closure of the said circuit-controllers, means for prolonging the period of engagement of the contacts which direct such current to the accelerating means by advancing such contacts while in engagement and means for restoring said contacts to normal position when separated.

3. In a synchronizing clock system, the combination with each secondary clock of means for advancing the hands of the same at a rate greater than normal, of a circuitcontroller which actuates at given times such advancing means for periods normally equal to those which measure the extent to whlch the clock may be slow, and means for prolonging the operative effect of said controller to permit the hands of the clock to advance to an extent 'to make up the full amount of lost. time.

I 4. In a synchronizing clock system, the combination with a secondary clock of means for advancing the hands of the same at a rate greater than normal, of a circuitcontroller which actuates at given times such advancing means for periods normally equal to those which measure the extent to which the clock may be slow, of means for advancing the controller so as to prolong its operative effect upon said means, and means for restoring the controller to normal position when the clock has made up its lost time.

5. Ina secondary synchronizing clock, th

combination with the driving train of a differential gear one driving member of which is normally free to revolve and the other of which is normally locked, of a circuit-controller for releasing the locked member when the clock is too slow and means for prolongingthe operative effect of said controller to compensate for the rate of advance and thereby permit the clock to make np its lost time.

6. In a secondary synchronizing clock, the combination with means for advancing the hands "at .a rate greater than normal, of a circuit-controller for actuating said means at definite times, of a rotary support for said controller and a clutch magnet which causes said support to advance and thereby prolong the operative effect of the same during the period of current flow through the controller.

7 The circuit-controller herein described, comprising in combination a p air of contacts, a cam disk on the hour shaft of a clock for closing the same for definite intervals, a rotary support for said contacts, and a clutch magnet for advancing said support whilev current is flowing through the controller.

8. In'a synchronizing clock system, the means for bringing into-synchronism with the master clock those secondary clocks that may be too slow comprising in combination means in the secondary clock for advancing the hands at a rate greater than normal, a circuit-controller for actuating at definite intervals such means, and means for prolonging the operative eflect of such circuitcontrollers so that the relatively higher rate of advance of the hands may, during the periods of their accelerated movement, bring the clock up to synchronism.

In testimony whereof I flix my signature.

JAMES W. BRYCE. 

